In buildings having a number of elevators and more than a few floors, the peak traffic periods (morning and evening) may be provided with special traffic handling service called "channeling". In this method of service, instead of all of the elevators serving all of the floors, the floors are divided into distinct, contiguous groups, with each elevator on each trip serving only one of the groups, thereby concentrating the stops which the elevator must make to only a few floors, instead of all the floors in the building. During down peak (evening), passengers easily select the right elevator because only the elevator serving the group will stop at floors for down calls. On the other hand, during up peak (morning), a passenger must determine which elevator is serving the group of floors within which the destination lies. Because each elevator has a different distance to travel round trip, depending on the channeling group it serves, the elevators are assigned to a next group of floors in turn as each elevator approaches the lobby for another run. Therefore, each elevator services successively different groups in dependence upon the particular number of elevators in service, number of groups being served, round trip run times, and the like. Therefore, even for passengers who enter the building day after day, it is impossible for them to know which elevator will serve them each morning. Therefore, elevator systems which employ channeling have floor enunciator panels, usually electroluminescent displays (ELDs), adjacent to or above the doors of each elevator so that as an elevator approaches the lobby floor, the panel indicates to potential passengers which floors the elevator will serve on the next trip. This permits the passengers to congregate at the elevator and board it when the time is appropriate. In more sophisticated elevator channeling systems, not only does the assignment of a group to each elevator change, the floors within a group will change from time to time, depending upon the traffic patterns and the optimum grouping of floors. Channeling systems of this type are shown in U.S. Pat. Nos. 4,838,384 and 4,846,311. While it may be relatively simple to listen for a gong and look for an enunciator light to determine which car is the next car up in a non-channeling system, actually reading the numbers on the panels of a channeling system is a lot more difficult. For vision impaired persons, determining which elevator to take can be totally impossible.
In handling traffic during up peak in systems that don't employ channeling, or in handling traffic at non-lobby floors, the situation is somewhat simpler since each car has an enunciator or lantern which typically includes both a light and a sounding device such as a chime. Typically, the particular direction from which the single sounding of a chime comes may not assist a passenger in determining which elevator will provide service, and sometimes the lights are difficult to see. For those who are color blind, the color of the light may be no clue as to whether the car is going up or down; the information eludes visually impaired persons.
In some elevator systems, operation in an up-peak traffic mode mandates the lack of upward service from any floors except the lobby, because such service disrupts the channeling or other up-peak traffic scheme. In such cases, passengers must first travel to the lobby and then travel upwardly to the floor of destination. For passengers who are not familiar with this mode of operation, the inability to register an up call can be disconcerting indeed.
In a similar fashion, the mere inability to react properly with an elevator system is stressful to some passengers. Thus, the fact that there does not appear to be any response from the system can be the most disconcerting of all. Furthermore, even though the system indicates recognition of the desire for service, if the service is not forthcoming within some reasonable time, passengers can become fretful about whether or not service will ever be forthcoming. Therefore, long delays in responding to a call can be extremely stressful to some passengers.
During fires and other emergencies, elevators are to be used only by professionals (such as firemen) and are not available to passengers. Therefore, elevators typically are simply non-responsive to passengers, which adds to their panic in an emergency situation. Although stairs are supposed to be utilized, there typically is no indication at an elevator as to which direction the nearest stairs are. If there is such an indication, it is typically a visible sign which may or may not be seen, particularly in the event of smoke, or loss of power for illumination, and so forth, or by visually impaired persons.
A similar situation may exist for passengers unfamiliar with a building whenever a double deck elevator is in use. In such systems, all of the passengers who are heading for an even numbered floor will utilize one elevator lobby which provides access to one of the decks of the double deck elevator, while those heading for an odd numbered floor will utilize a different elevator lobby which provide access to the opposite deck of the elevator car. Then, as it travels upwardly in the building, each time that a car stops, one set of passengers are allowed access to an even numbered floor while the other set of passengers are simultaneously allowed access to an odd numbered floor. In this way, two floors are satisfied with each stop of the elevator, and a single elevator shaft can carry twice the normal number of passengers during the up-peak mode of operation. During down peak, the converse is true and passengers will enter whichever deck of the elevator is presented to the floor from which they request service, so there is no problem.
During periods of heavy traffic, it is sometimes difficult for a passenger to know whether he should push into a crowded elevator car or wait for the next car; this problem can become worse if the passengers should enter as a group, such as may be true with an adult accompanying several children. It is hard to tell if the car is really full, and for persons in a hurry, it is hard to know how long it may take before another car may provide service.
For some people, the mere usage of elevators provides anxiety (not unlike that for those with a fear of flying). All of the foregoing problems are compounded for those persons for whom use of elevator systems is stressful.